Stefan Bradl (Viessmann Kiefer Racing, Kalex) was declared the Moto2 World Champion after vision problems forced title rival Marc Márquez (Team CaixaCatalunya Repsol, Suter) out of Saturday morning qualifying at the Valencia Grand Prix, forcing the Spaniard to withdraw from the final race of the 2011 season.Marquez had arrived at the season finale hopeful of derailing Bradl, but his chances were slim from the start. In order to win the title, Marquez had to win the race and hope that Bradl, 21, from Germany, finished 14th or worse. It wasn't as far-fetched at it seemed; in four races, Bradl has never finished a grand prix at Valencia.Marquez's team issued a Saturday morning press release stating that Marquez "tried to wait until the last moment to take advantage of any chance to be able to fight tomorrow for the Moto2 title, but he was not able to recover in time from his sight problems due to the crash he suffered on Friday morning in the Malaysian GP."The irony is that crash in Malaysia wasn't his fault. Corner marshals at the Sepang Circuit failed to warn riders of a wet track in turn ten on Friday morning practice. Three riders crashed, including Marquez, who fell heavily on his head. The young Spaniard suffered double vision, which hasn't cleared up in the two weeks since the accident. He finishes the season with seven wins, seven poles, 11 podiums, and two fastest race laps.Heading into Sunday's race, Bradl has four wins, all of which came in the first six races. His final win came in the rain-sodden British Grand Prix back in June. Marquez won the next race in Assen, while Bradl crashed near the end of the race. It marked a pivotal point in the championship, with the yawning points gap Bradl once enjoyed suddenly reduced by 25 points.For the next seven races, Marquez continued to finish in front of Bradl, the points lead continuing to shrink until the Japanese Grand Prix where Marquez took the lead by a single point after finishing second to Bradl's fourth.But Marquez's fortunes immediately reversed. In practice at Phillip Island, he rammed Ratthapark Wilairot on the cooldown lap, earning a one second penalty on his qualifying time. Starting from the back of the grid, he made a spirited run to the front, finishing third to Bradl's second. Bradl carried a three point lead going into Malaysia. Just minutes into the Malaysian practice Marquez was down and, eventually, out.Bradl becomes the eighth German solo class world champion and first since 1993, when Dirk Raudies won the 125cc title. The last German to win the intermediate class crown was Anton Mang, who won the last of his five 250cc titles in 1987. Bradl's father, Helmut, was second in the 1991 250cc World Championship to Luca Cadalora.